Process of manufacturing optical fibers of extremely low loss in the medium infrared

Abstract

The process of manufacturing optical fibers of extremely low loss in the medium infrared permits the fabrication of glass preforms having as basic materials metal-fluorides obtained from vapor-phase reactants.

I claim: 
     
       1. In a process for manufacturing optical fibers of extremely low loss in transmission of infrared radiation, wherein a preform from which the fibers are drawn is made from metal fluoride glass obtained by vapor phase reaction and deposition on a substrate, the improvement wherein said glass is obtained by the reaction between a gaseous reactant containing fluorine and an organometallic compound of the formula   M(C.sub.γ H.sub.δ).sub.ψ A.sub.η     where M represents a metal whose fluoride is to be obtained by reactive synthesis, C is carbon, H is hydrogen, A is a halogen, and symbols γ, δ, ψ, η are all at least equal to one and represent the molecular coefficients of atoms C, H, of group CH and of halogen A respectively.   
     
     
       2. The improvement defined in claim 1 wherein said gaseous reactant containing fluorine is selected from the group consisting of:   F.sub.2, CCl.sub.2 F.sub.2, CClF.sub.3, and CF.sub.4     
     
     
       3. The improvement defined in claim 1 wherein said reaction is obtained inside a supporting tube made of oxide glass, the material produced is deposited inside the same tube, and the inside surface of said supporting tube is enriched with fluorine by thermal diffusion.